Oh, vertically align within the entire browser window ... ok, that is more challenging even with tables.
However, it can be done and still looks to be much simpler and more predictable than using CSS alone - see the following link for details ...
http://apptools.com/examples/tableheight.php
Tables and CSS together is likely your best bet for compatibility with recent browsers.
Or if in a rush and "quirks mode" is good enough (it may be if your site already is already being rendered that way by default; many sites still are), then just add in the table attributes
height="100%" - but as the above link points out, that's not recommended, because the height attribute, according to the article and based on my own experience, has never been part of any W3 html standard.
Ron